当前位置: 首页 > 图文教程 > 网络编程 > ASP.NET > asp.net 需要登陆的网站上下载网页源代码和文件

ASP.NET
如何在ASP.NET中使用SmtpMail发送邮件
在VB.NET中利用Split和Replace函数计算字数
Attribute应用:简化ANF自定义控件初始化过程
ASP.NET 2.0移动开发入门之使用样式
ASP.NET 2.0中使用OWC生成图表
ASP.NET 2.0中控件的简单异步回调
一个无法捕获ADO.NET Dataset的内存错误
深入解读ADO.NET2.0的十大最新特性
.Net平台下的分布式缓存设计
ASP.NET全局异常处理浅析
ASP.NET 2.0中文验证码的实现
浅析.NET平台编程语言的未来走向
.net 框架程序设计收藏
使用ASP.NET MVC Futures 中的异步Action
详解.NET中的XmlReader与XmlWriter
关于.NET中的Server push技术
asp.net页面执行机制
对比JSP和ASP.NET的存储过程
.NET 4.0不会包含System.Shell.CommandLine
ASP.NET十个有效性能优化的方法

ASP.NET 中的 asp.net 需要登陆的网站上下载网页源代码和文件


出处:互联网   整理: 软晨网(RuanChen.com)   发布: 2009-09-13   浏览: 120 ::
收藏到网摘: n/a

最近有个项目需要从网络上下载网页信息和文件,并且需要登录后才能下载,所以做了个下载的通用类,供大家参考。 这个是文件下载类:
复制代码 代码如下:

using System;
using System.IO;
using System.Net;
using System.Web;
public class SRWebClient
{
CookieContainer cookie;
public SRWebClient()
{
cookie = new CookieContainer();
}
/// <TgData>
/// <Alias>下载Web源代码</Alias>
/// </TgData>
public string DownloadHtml(string URL)
{
HttpWebRequest request = HttpWebRequest.Create(URL) as HttpWebRequest;
request.CookieContainer = cookie;
request.AllowAutoRedirect = false;
WebResponse res = request.GetResponse();
string r = "";
StreamReader S1 = new StreamReader(res.GetResponseStream(), System.Text.Encoding.Default);
try
{
r = S1.ReadToEnd();
}
catch (Exception er)
{
Log l = new Log();
l.writelog("下载Web错误", er.ToString());
}
finally
{
res.Close();
S1.Close();
}
return r;
}
/// <TgData>
/// <Alias>下载文件</Alias>
/// </TgData>
public long DownloadFile(string FileURL, string FileSavePath)
{
long Filelength = 0;
HttpWebRequest req = HttpWebRequest.Create(FileURL) as HttpWebRequest;
req.CookieContainer = cookie;
req.AllowAutoRedirect = true;
HttpWebResponse res = req.GetResponse() as HttpWebResponse;
System.IO.Stream stream = res.GetResponseStream();
try
{
Filelength = res.ContentLength;
byte[] b = new byte[512];
int nReadSize = 0;
nReadSize = stream.Read(b, 0, 512);
System.IO.FileStream fs = System.IO.File.Create(FileSavePath);
try
{
while (nReadSize > 0)
{
fs.Write(b, 0, nReadSize);
nReadSize = stream.Read(b, 0, 512);
}
}
finally
{
fs.Close();
}
}
catch (Exception er)
{
Log l = new Log();
l.writelog("下载文件错误", er.ToString());
}
finally
{
res.Close();
stream.Close();
}
return Filelength;
}
/// <TgData>
/// <Alias>提交数据</Alias>
/// </TgData>
public void Request(string RequestPageURL, RequestData Data)
{
string StrUrl = RequestPageURL;
HttpWebRequest request = HttpWebRequest.Create(StrUrl) as HttpWebRequest;
HttpWebResponse response;
string postdata = Data.GetData();
request.Referer = RequestPageURL;
request.AllowAutoRedirect = false;
request.UserAgent = "Mozilla/4.0 (compatible; MSIE 6.01; Windows NT 5.0)";
request.CookieContainer = cookie;
Uri u = new Uri(StrUrl);
if (postdata.Length > 0) //包含要提交的数据 就使用Post方式
{
//作为表单请求
request.ContentType = "application/x-www-form-urlencoded";
//方式就是Post
request.Method = "POST";
//把提交的数据换成字节数组
Byte[] B = System.Text.Encoding.Default.GetBytes(postdata);
request.ContentLength = B.Length;
Stream SW = request.GetRequestStream(); //开始提交数据
SW.Write(B, 0, B.Length);
SW.Close();
}
response = request.GetResponse() as HttpWebResponse;
response.Close();
}
}

这个是提交的数据类:
复制代码 代码如下:

using System.Collections;
using System.IO;
public class RequestData
{
ArrayList arr = new ArrayList();
public RequestData()
{
}
public string GetData()
{
string r = "";
for (int i = 0; i < arr.Count; i++)
{
data d = (data) arr[i];
if (r.Length > 0)
r += "&";
r += d.Field + "=" + d.Value;
}
return r;
}
public void AddField(string Field, string Value)
{
data a = new data();
a.Field = Field;
a.Value = Value;
arr.Add(a);
}
struct data
{
public string Field, Value;
}
}

代码贴完了,下面是测试代码,因为有些数据涉及到客户的资料,故隐去
复制代码 代码如下:

using NUnit.Framework;
[TestFixture]
public class TestWeb
{
[Test]
public void testDownSEOrder()
{
RequestData data = new RequestData();
data.AddField("name", "abc");
data.AddField("password", "121");
SRWebClient web = new SRWebClient();
web.Request("http://127.0.0.1/login.asp", data);
string s = web.DownloadHtml("http://127.0.0.1/dingdan.asp");
System.Console.WriteLine(s);
}
[Test]
public void testDownFile()
{
RequestData data = new RequestData();
data.AddField("name", "aaa");
data.AddField("password", "bbb");
SRWebClient web = new SRWebClient();
web.Request("http://127.0.0.1/login.asp", data);
web.DownloadFile("http://127.0.0.1/download.asp?fileid=1", @"c:\a.txt");
}
}